msem-instigator

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)

When Thailen's Guard dies, you gain 2 life and scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

When Thallid Cultivator dies, mill four cards. Return a creature card milled this way to your hand.

Whenever one or more cards leave your graveyard, put a soul counter on this creature.
This creature gets +1/+1 for each soul counter on it.
{1}{W}, Exile a creature card from your graveyard: This creature gains indestructible until end of turn. Tap it.

Whenever another legendary creature you control enters, put a +1/+1 counter on The Lost and Seeking.
Surpass {4}{R}{W} ({4}{R}{W}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

As The Mistake enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.
Unveil {5} ({5}: Transform this. Unveil only as a sorcery.)

When The Raven Queen of Fretport enters, put a -1/-1 counter on each of any number of target creatures.
{2}{U}{B}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flying
Whenever one or more other creatures die for the first time each turn, journey. (To journey, exile the top card of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

Prowess
Whenever you cast a noncreature spell, audition for blue or for red. (Create a 1/1 Construct Actor creature token, a Wizard Role giving 2/2 and prowess, a Warlock Role giving 2/1 and flying, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)

{T}: Draw a card. Activate only if Theoretical Scholar is embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Thorn Tender enters, rouse 1, then put a +1/+1 counter on each creature you control. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Thuggish Detective can't be blocked by more than one creature.
When Thuggish Detective becomes renowned, you may destroy target noncreature permanent.

Flying
Tianyuren Skycharter has hexproof as long as you control a storied permanent. (Enchantments and legendary permanents are storied.)

Flash
Menagerie — When Tidal Trickster enters, if there are five or more creature types among creatures you control, you may search your library for a card named Tidal Trickster, reveal it, put it into your hand, then shuffle.

Lionize {1}{U} ({1}{U}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {X}, where X is this creature's power.

Kicker {X}{U} (You may pay an additional {X}{U} as you cast this spell.)
When Tidetwister Mage enters, if it was kicked, return all other creatures with power X or less to their owners' hands.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)

{3}: Put a +1/+1 counter on Tinkerer's Assistant.

Rapport — Whenever Tinkering Swarm and at least one other creature you control become tapped, create a token that's a copy of Tinkering Swarm.

Prowess
Whenever you cast an instant or sorcery spell, Tirenan Pyromancer deals 1 damage to each opponent.

Flying
Whenever another creature you control enters from a graveyard or you revive a creature token, Tomb Scavenger gets +2/+0 until end of turn.

When Tombstone Looter enters, you may draw a card. If you do, discard a card.
Unearth {1}{U} ({1}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

Ward {2}
Even numbered spells you cast each turn costs {2} less to cast. (The second, fourth, sixth, etc.)

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Topan Curemaster encourages a creature, you gain 1 life.